Rod Material Forming with Polygonal Dishing Tool
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing formed parts with through holes often result in undesirable fracture surfaces and burrs, requiring significant reworking and material waste, especially when separating completed parts from rod material.
Innovation Solution
A method involving axial penetration and impact extrusion of rod material within a forming die, followed by torsional separation using a dishing tool, with a stationary clamping arrangement to secure the rod material and ensure clean separation without burrs, utilizing a forming die with radial elasticity for enhanced frictional locking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If axial perforation is performed with a punch having the same cross-sectional shape as the rod material, then the formed part is separated from the rod material, but fracture surfaces with cracks and burrs occur on the peripheral edge of the hole
Solution Approach 1:
The invention changes the cross-sectional shape parameter of the penetrating tool from circular (matching the rod) to polygonal (e.g., hexagonal). This parameter change modifies the stress distribution during penetration, preventing the generation of cracks and burrs on the hole's peripheral edge while maintaining effective separation of the formed part from the rod material.
2Loss of substance
If the disc core and uncompressed rod material portion are kept as an integral part for subsequent processing, then material waste is reduced, but the fracture surface quality deteriorates due to stress concentration at the interface
Solution Approach 1:
By changing the cross-sectional shape of the penetrating tool to a polygonal form, the stress distribution during separation is optimized. This prevents stress concentration at the interface between the disc core and remaining rod material, thereby maintaining high fracture surface quality while preserving material integrity for subsequent processing.
3Ease of manufacture
If conventional punching methods are used to separate formed parts from rod material, then the separation process is simple, but significant reworking is required due to burrs and deformations
Solution Approach 1:
The invention maintains the simplicity of the punching separation process by using a polygonal-cross-section tool instead of a circular one. This parameter change eliminates the need for subsequent reworking of burrs and deformations, thereby reducing reworking time while keeping the manufacturing process straightforward.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method produces formed parts with minimal deformation and no burrs, allowing for efficient processing and reducing material waste by enabling long rod material usage without the need for additional forging dies, thus improving the separation process and reducing reworking requirements.
Implementation Method 1
The portion of the rod material located inside the forming die is penetrated axially and at the same time impact extruded by at least one dishing tool, wherein the displaced material flows between the at least one dishing tool and the inner circumferential wall of the forming die.
Implementation Method 2
The formed part that is created in this manner and is located inside the forming die, is rotated coaxially relative to the rest of the rod material together with the forming die surrounding it and the at least one dishing tool, and the formed part is thus separated from the rest of the rod material.
Implementation Method 3
a rod material is advanced by a defined length in the direction of its lengthwise extension into a forming die... and the rod material is then immobilised axially
Data Source
AI summary
In order to produce a formed part furnished with a through hole, a rod material is advanced by a defined length in the direction of its lengthwise extension into a forming die through a stationary guide and then immobilised by a clamping arrangement that engages with it circumferentially. The end portion of the rod material is then axially swaged by a swaging tool and is thus shaped into a disc, the circumference of which is defined by the forming die. The disc is then penetrated axially by a dishing tool and impact extruded at the same time, the displaced material flowing between the dishing tool and the inner circumferential wall of the forming die. The formed part located in the forming die is then rotated coaxially relative to the rest of the rod material and thereby separated from the rest of the rod material by torsion shearing.